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What is the correct answer?

4

Gibbs-Helmholtz equation is

A. ΔF = ΔH + T [∂(ΔF)/∂T]P

B. ΔF = ΔH - TΔT

C. d(E - TS) T, V < 0

D. dP/dT = ΔHvap/T.ΔVvap

Correct Answer :

A. ΔF = ΔH + T [∂(ΔF)/∂T]P


Related Questions

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4

The equation, (d loge PA/d loge xA) = (d loge PA/d loge xB) applicable to a binary solution of components. A and B in equilibrium with their vapors at constant temperature and pressure is called the __________ equation.

A. Van Laar

B. Margules

C. Gibbs-Duhem

D. Gibbs-Duhem-Margules

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4

Variation of equilibrium pressure with temperature for any two phases of a given substances is given by the __________ equation.

A. Gibbs-Duhem

B. Maxwell's

C. Clapeyron

D. None of these

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4

Any substance above its critical temperature exists as

A. Saturated vapour

B. Solid

C. Gas

D. Liquid

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4

Which of the following is not an intensive property?

A. Molar heat capacity

B. Internal energy

C. Viscosity

D. None of these

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4

Pick out the correct statement:

A. In an isothermal system, irreversible work is more than reversible work

B. Under reversible conditions, the adiabatic work is less than isothermal work

C. Heat, work, enthalpy and entropy are all 'state functions'

D. Matter and energy cannot be exchanged with the surroundings in a closed system

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4

Maxwell's relation corresponding to the identity, dH = dS = Vdp + Σμi dni is

A. (∂T/∂V)S, ni = -(∂P/∂S)V, ni

B. (∂S/∂P)T, ni = (∂V/∂T)P, ni

C. (∂S/∂V)T, ni = (∂P/∂T)V, ni

D. (∂T/∂P)S, ni = (∂V/∂S)P, ni

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4

In vapour compression refrigeration system, if the evaporator temperature and the condenser temperatures are -13°C and 37°C respectively, the Carnot COP will be

A. 5.2

B. 6.2

C. 0.168

D. Data insufficient, can't be found out

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4

For equilibrium process (i.e. reversible) in an isolated system

A. ds = 0

B. ds < 0

C. ds > 0

D. ds = Constant

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4

For a constant pressure reversible process, the enthalpy change (ΔH) of the system is

A. Cv.dT

B. Cp.dT

C. ∫ Cp.dT

D. ∫ Cv.dT

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4

Degree of freedom of a system consisting of a gaseous mixture of H2 and NH3 will be

A. 0

B. 1

C. 2

D. 3

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4

For a single component two phase mixture, the number of independent variable properties are

A. Two

B. One

C. Zero

D. Three

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4

For an irreversible process involving only pressure-volume work

A. (dF)T, p <0

B. (dF)T, p = 0

C. (dF)T, p > 0

D. (dA)T, v >0

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4

Degrees of freedom at triple point will be

A. 0

B. 1

C. 2

D. 3

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4

If two gases have same reduced temperature and reduced pressure, then they will have the same

A. Volume

B. Mass

C. Critical temperature

D. None of these

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4

At the critical point of a substance

A. The surface tension vanishes

B. Liquid and vapour have the same density

C. There is no distinction between liquid and vapour phases

D. All (A), (B) and (C)

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4

Helmholtz free energy (A) is defined as

A. A = H - TS

B. A = E - TS

C. A = H + TS

D. None of these

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4

In any spontaneous process,

A. Only F decreases

B. Only A decreases

C. Both F and A decreases

D. Both F and A increase

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4

A closed system is cooled reversibly from 100°C to 50°C. If no work is done on the system

A. its internal energy (U) decreases and its entropy (S) increases

B. U and S both decreases

C. U decreases but S is constant

D. U is constant but S decreases

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4

Sublimation temperature of dry ice (solid CO2) is __________ °C.

A. -273

B. 0

C. -78

D. 5

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4

The equation relating E, P, V and T which is true for all substances under all conditions is given by (∂E/∂V)T = T(∂P/∂T)H - P. This equation is called the

A. Maxwell's equation

B. Thermodynamic equation of state

C. Equation of state

D. Redlich-Kwong equation of state

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4

Pick out the wrong statement.

A. A closed system does not permit exchange of mass with its surroundings but may permit exchange of energy.

B. An open system permits exchange of both mass and energy with its surroundings

C. The term microstate is used to characterise an individual, whereas macro-state is used to designate a group of micro-states with common characteristics

D. None of the above

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4

Co-efficient of performance for a reversed Carnot cycle working between temperatures T1 and T2 (T1 > T2) is

A. T2/(T1 - T2)

B. T1/(T1 - T2)

C. (T1 - T2)/T1

D. (T1 - T2)/T2

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4

The chemical potential for a pure substance is __________ its partial molal free energy.

A. More than

B. Less than

C. Equal to

D. Not related to

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4

A/an __________ system is exemplified by a vessel containing a volatile liquid in contact with its vapor.

A. Isolated

B. Closed

C. Open

D. None of these

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4

Pick out the wrong statement

A. Phase rule variables are intensive properties

B. Heat and work are both state function

C. The work done by expansion of a gas in vacuum is zero

D. CP and CV are state function

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4

In polytropic process (PVn = constant), if n = 1; it means a/an __________ process.

A. Adiabatic

B. Reversible

C. Isothermal

D. None of these

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4

The first law of thermodynamics is a statement of conservation of

A. Heat

B. Momentum

C. Energy

D. Work

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4

The gas law (PV = RT) is true for an __________ change.

A. Isothermal

B. Adiabatic

C. Both (A) & (B)

D. Neither (A) nor (B)

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4

The expression for the work done for a reversible polytropic process can be used to obtain the expression for work done for all processes, except reversible __________ process.

A. Isobaric

B. Isothermal

C. Adiabatic

D. None of these

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4

Work done in case of free expansion is

A. Indeterminate

B. Zero

C. Negative

D. None of these